When the http:// stream wrapper follows a redirect it forwards the user-supplied Authorization, Cookie and…
Summary
Vulnerability reported (CVE-2026-91766). Confidential information can be exposed externally. Exploitable via Authorization header. Mitigation: upgrade to 7.58.0 or later.
Original description
The description as published by the source.
When the http:// stream wrapper follows a redirect it forwards the user-supplied Authorization, Cookie and Proxy-Authorization headers unchanged, even when the redirect target is a different host, a different port, or a downgrade from HTTPS to HTTP. A server that can steer a redirect therefore receives credentials that were only meant for the original origin. This is the same class of issue that libcurl fixed in 7.58.0 ( CVE-2018-1000007 https://github.com/advisories/GHSA-g7x2-hrfp-pv5f ).
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-91766 has been found.
Attackers can target a specific entry point like Authorization header over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 5.9/10.
What to do: upgrade the affected software to 7.58.0 or later.
If unsure, ask your IT team or search "CVE-2026-91766" on the vendor's site.
CVE-2026-91766 — CWE-200 / CVSS v3 5.9
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Authorization header
Patched: 7.58.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Information disclosure (CWE-200) has been reported. Attackers reach the vulnerable code path via Authorization header without authentication.
Check the vendor advisory for the affected versions. Attack surface: Authorization header.
Severity: Medium (CVSS 5.9/10). Confidential information can be exposed externally.
Update to 7.58.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで影響コンポーネントを特定する。
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2Apply patch patch
Upgrade to 7.58.0ステージング環境で 7.58.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- web security@php.net